http://www.wired.com/news/technology/0,71087-0.html
How random.
What if, seconds before your laptop began stalling, you could feel the hard drive spin up under the load? Or you could tell if an electrical cord was live before you touched it? For the few people who have rare earth magnets implanted in their fingers, these are among the reported effects -- a finger that feels electromagnetic fields along with the normal sense of touch.
Appliance cords in the United States give off a 60-Hz field, a sensation with which Huffman has become intimately familiar. "It is a light, rapid buzz," he says.
How random.